Device for surface hardening of parts

ABSTRACT

A device for hardening the surfaces of parts by means of plastic deformation. The device permits hardening bodies to be admitted by gravity into a chamber from an additional chamber by opening a valve which normally closes a hole between the two chambers. The valve is then closed and a stream of compressed air is admitted to propell the hardening bodies to harden the surface of parts. The hardening bodies can be caused to reenter the additional chamber upon completion of a hardening operation by opening the valve while the stream of compressed air is being applied.

United States Patent Osmolovsky et al.

July 11, 1972 DEVICE FOR SURFACE HARDENING OF PARTS [72] Inventors: JuryAmtnlievieh Oanolovsky, Pisarevsky proezd, 3. kv. 47, PushkinoMoskowskoi Oblasti; Anatoly Senflmovlch Kizilyaev, ulitsa 8 Marta, 7,kv. 118, Ljubertsy Moskovskoi Oblasti, both of U.S.S.R.

[22] Filed: March 18, 1970 [2!] Appl.No.: 20,662

[52] U.S.Cl. ..72/53,5l/ll [5]] Int. Cl. C2ld7/06 [58] FieldolSeare-h..72/53;29/90, 90.1,901, 90.3,

29/906, 908, DlG. 36; Sill l [56] References Cited UNITED STATES PATENTS2,70l,408 2/1955 Borger v.72/53 Primary Examiner-Charles W. LanhamAssislanl Examiner-Gene P. Crosby Attorney-Waters, Roditi, Schwartz &Nissen ABSTRACT A device for hardening the surfaces of pans by means ofplastic deformation. The device permits hardening bodies to be admittedby gravity into a chamber from an additional chamber by opening a valvewhich normally closes a hole between the two chambers. The valve is thenclosed and a stream of compresed air is admitted to propell thehardening bodies to harden the surface of parts. The hardening bodiescan be caused to reenter the additional chamber upon completion of ahardening operation by opening the valve while the stream of compressedair is being applied,

ZChiugZDrawlngFigum DEVICE FOR SURFACE HARDENING F PARTS The presentinvention relates to devices for the surface hardening of parts byplastic deformation and more specifically to devices for the hardeningof parts with the aid of hardening bodies activated by a stream ofcompressed gas.

Devices are known for the hardening of parts by the use of hardeningbodies in the form of metal balls propelled by a stream of compressedair. These devices consist of a casing which, together with the surfaceof the workpiece, forms a chamber for holding the hardening bodies inthe process of hardening, and of an apparatus for collecting thehardening bodies on the completion of said process.

The chamber holding the metal balls during the hardening process is incommunication with a compressed air line and, through holes in thecasing walls, with the ambient atmosphere.

The apparatus for collecting the metal balls on completion of thehardening process is made in the form of an electromagnet whose core isconstituted by the casing of the device.

In the known type of device, it is necessary, for holding the metalballs in the chamber after the compressed air supply has been cut off,to switch on the electromagnet. This complicates the design of thedevice because, apart from the supply of compressed air, it must have alow-voltage D.C. supply.

in addition, for holding the balls during the intervals between thehardening operations, the casing of the device must be kept energized,and this is extremely inconvenient in operation.

An object of the present invention resides in eliminating the aforesaiddisadvantages.

A more specific object of the invention resides in providing a devicefor the surface hardening of parts wherein the apparatus for collectingthe hardening bodies after the hardening cycle collects the hardeningbodies by utilizing the energy of the compressed gas used for hardening.

The above objects are accomplished by providing a device for the surfacehardening of parts with hardening bodies propelled by a stream ofcompressed gas, said device including a casing open at one said andforming, together with the surface of the part being hardened, a chamberfor holding the hardening bodies in the process of hardening, saidchamber communicating with the compressed air line and, through holes inthe casing, with the atmosphere, and an apparatus for collecting thehardening bodies after the end of the hardening process. According tothe invention, the apparatus for collecting the hardening bodies is anadditional chamber which communicates with the chamber which holds thehardening bodies during the hardening process through a hole covered bya valve. Additionally, through holes in its wall the additional chambercommunicates with the atmosphere.

A device for the cold work hardening of parts realized in accordancewith the present invention is simple to manufacture and easy to use inoperation.

The invention will next be described in detail by way of example withreference to the accompanying drawings in which:

FIG. 1 is a longitudinal section through a device for the surfacehardening of parts according to the invention; and

FIG. 2 is a view in the direction of arrow A in FIG. 1.

In the drawing, a device for the surface hardening of a part 1 (FIGS. 1,2) comprises a casing 2 mounted in a holder 3. The casing 2 is made of,for example, polyfluoroethylene resin or caprolan. The casing 2 iscone-shaped and its narrower part accommodates a nozzle 4 connected withthe compressed air line 5 while its wider open part is in contact withthe surface of the part 1 being hardened. The casing 2 and the surfaceof the part 1 forms a chamber 6 which holds the hardening bodies 7 inthe course of a hardening operation. The hardening bodies 7 have theform of metal balls. The hardening bodies can also be constituted by anyobjects having a rounded shape. They may be made of plastic or othernonmetallic materials.

For putting the chamber 6 in communication with the atmosphere, thewalls of the casing 2 have holes 8 whose size is smaller than that ofthe hardening bodies 7. The compressed air entering the chamber 6 foruse in hardening the part 1 escapes through these holes into theatmosphere.

Installed on the wider open part of the casing 2 is a flexible element 9which, fitting tightly against the surface of the part 1, makes itpossible to follow the shape of the surface being hardened. The flexibleelement 9 has a hole 10 whose shape corresponds to that of the part 1being hardened. If the surface to be hardened is flat, the hole 10 ofthe flexible element 9 is round which insures a maximum area for thehardened surface of the part 1. The flexible element 9 is held in thecasing 2 and holder3 by a nut 11.

The casing 2 has a threaded hole 12 receiving an apparatus 13 forcollecting the hardening bodies 7 after the processing of the surface ofthe part 1.

The apparatus 13 is made in the form of an additional chamber 14 whichcommunicates with the chamber 6 through the hole 12. The hole 12 iscovered by a valve l5. This valve is connected to one end of a rod 16while the other end of said rod carries a handle l7.

Located on the rod 16 between the handle 17 and the additional chamber14 is a spring 18 which holds the valve 15 closed.

The walls of the additional chamber 14 are provided with holes 19communicating it with the atmosphere. The size of these holes is smallerthan that of the hardening bodies 7.

The casing 2 and a part of the holder 3 are enclosed by a housing 20which protects servicing personnel against the escaping jets ofcompressed air and reduces the level of noise produced when thehardening bodies strike the surface of the part being hardened.

The described device which is provided for the surface hardening ofparts operates as follows:

The additional chamber 14 is filled with 70-[00 g balls 7 of 2 or 3 mm.diameter. Then the apparatus 13 is screwed into the hole 12 of thecasing 2. The apparatus 13 is set at a certain angle in the casing 2 sothat the balls 7 are able to fall into the chamber 6 under their ownweight (the valve being open, as shown by dotted lines in FIG. 1).

After installation of the apparatus 13 in the casing 2 of the device,the latter is brought to the surface of the part 1 to be hardened untilit fits tightly against it. Then, by a pressing of the handle 17, thevalve 15 is opened (shown by dotted lines) and the balls fall undertheir own weight into the chamber 6.

Being acted upon by the spring 18, the valve 15 returns to the initialposition, closing the hole 12 in the casing 2. Then compressed air undera pressure of 3-6 atm. is admitted into the chamber 6. Being dischargedat a high speed from the nozzle 4, the air entrains the balls 7 and,having imparted its kinetic energy to them, escapes into the atmospherethrough the holes 8. The balls that have acquired a certain velocity,strike the surface of the part 1 and act to harden it.

On completion of hardening of the part 1, the valve l5 is opened by thehandle 17, without cutting off the supply of compressed air. The airunder pressure rushes into the additional chamber 14 due to therelationship between the total areas of holes 8 and 19 which provides apreferred path of escape for the compressed air, thereby propelling intosaid additional chamber the balls 7 which are collected in this chamberwithin a small period of time (not over 15 seconds).

Then the valve is closed and the supply of compressed air from the airline 5 is cut off. This completes the process of hardening the part Iand the device is withdrawn from the hardened surface.

For hardening the surface of bodies of rotation, e.g. torsion shafts,the device is secured to the tool holder of a turning lathe (not shown)whereas the parts 1 are set in the lathe centers. Then the part 1 isrotated and the device is moved progressively. This insures thehardening of the entire surface of the part. The flexible element 9which fits tightly against the surface being hardened prevents thecompressed air and the balls from escaping to the outside at the pointwhere part contacts said element.

For fitters work, for instance while straightening sheet metal, thedevice is held in a vertical position, being pressed against the surfaceof the part 1 by hand We claim:

17 A device for the surface hardening of parts by the use of hardeningbodies propelled by a stream of compressed air supplied through acompressed air line, said device comprising: a casing provided with anopening and forming, together with the surface of said part to behardened, a chamber for holding said hardening bodies in the course of ahardening operation; a nozzle mounted in said casing at a positionremote from said opening, for coupling said chamber with the compressedair line; said casing including a wall provided with holes forcommunicating said chamber with ambient atmosphere; means for collectingsaid hardening bodies, after a hardening process, arranged on saidcasing and having an additional chamber communicating with the firstsaid chamber for receiving and holding said hardening bodies after ahardening process, said additional chamber constantly communicating withambient atmosphere through holes provided in said means, the total areaof the holes in said means being related to the total area of the holesin the wall of said casing to provide a preferred path of escape of thecompressed air through the holes provided in said means; and a valvedisposed in said additional chamber for selectively separating saidadditional chamber from the first said chamber, in the course ofhardening, as well as after the collecting of said hardening bodies insaid additional chamber.

2. A device as claimed in claim 1 further comprising a spring loadingsaid valve, whereby said valve normally maintains said additionalchamber isolated from the first said chamber.

1. A device for the surface hardening of parts by the use of hardeningbodies propelled by a stream of compressed air supplied through acompressed air line, said device comprising: a casing provided with anopening and forming, together with the surface of said part to behardened, a chamber for holding said hardening bodies in the course of ahardening operation; a nozzle mounted in said casing at a positionremote from said opening, for coupling said chamber with the compressedair line; said casing including a wall provided with holes forcommunicating said chamber with ambient atmosphere; means for collectingsaid hardening bodies, after a hardening process, arranged on saidcasing and having an additional chamber communicating with the firstsaid chamber for receiving and holding said hardening bodies after ahardening process, said additional chamber constantly communicating withambient atmosphere through holes provided in said means, the total areaof the holes in said means being related to the total area of the holesin the wall of said casing to provide a preferred path of escape of thecompressed air through the holes provided in said means; and a valvedisposed in said additional chamber for selectively separating saidadditional chamber from the first said chamber, in the course ofhardening, as well as after the collecting of said hardening bodies insaid additional chamber.
 2. A device as claimed in claim 1 furthercomprising a spring loading said valve, whereby said valve normallymaintains said additional chamber isolated from the first said chamber.